* It's not a "crappy" RNG. Its RC4 origins and the fact, that it has passed tests indicate the opposite. A fast RNG doesn't necessarily mean a bad one. I doubt if any test will tell the difference between frandom and any other good RNG. You're most welcome to try.

* Frandom is written completely in C. On an i686, gcc compiles the critical part to 26 assembly instructions per byte, and I doubt if any hand assembly would help significantly. The algorithms is clean and simple, and the compiler performs well with it.